(TERRE HAUTE, Ind.) -- Prison inmates convicted of killing children typically have a rough road to hoe in the penitentiary, the underworld of convict society not looking kindly on such criminals.

But the killer of 10-year-old Katie Collman now has a particular marking that stands out amongst his peers: a tattoo across his forehead that reads "Katie's Revenge."

A photo showing the crude, homemade marking on the head of Anthony Stockelman surfaced on the Internet this week. Officials at the Wabash Valley Correctional Facility, where Stockelman is serving life without parole for molesting and strangling the southern Indiana child, confirmed they are investigating how the tattoo was applied.

Collman's father, John Neace, learned of the tattoo after friends from Georgia called him on Tuesday. They had set alerts for the name 'Stockelman' on their Google search engine, he said.

"I think it's a statement being made, by, in my guess, the inmates," Neace told WAVE 3 Investigator James Zambroski during an interview in Crothersville, Ind., where Katie was murdered.

Stockelman was arrested for the killing after his DNA was found on a cigarette near where Katie's body was found in a creek about 10 miles from Crothersville. Later investigation revealed his DNA on her body as well. He pled guilty in order to avoid a death sentence.

Prison officials are investigating whether other inmates forcibly applied the crude lettering to Stockelman's forehead. Internet reports state, and Neace confirmed, that one of Katie's cousins is serving a sentence at Wabash. His name is different than Katie's, a fact that apparently caused officials to miss the relationship between Katie and the inmate.

Neace said he'd not heard of any connection between his cousin and the tattoo; corrections officials would only say a investigation is continuing.

"I've never seen anything like it before; I've never even heard of anything like it," Neace said of the tattoo.

Even if Stockelman was attacked and had the tattoo forcibly applied, there is little sympathy for him in Katie's hometown of Crothersville.

"Some of the early interviews that they had with him when he was in prison, when he first got there, was that it was kind of like a vacation to him, wasn't bad at all," said Terry Gray, a family friend.

"I'd say he probably had a change of heart about that now," he said.

The tattoo, Gray said, is some kind of prison message. "I think that would be in this order, I think it was meant to be weird justice," he said.

And perhaps a sign of days ahead for Stockelman.

"I figure that probably Mr. Stockelman was given the choice of a tattoo or facing the same fate as Katie did," he said.

In the end, a prison sense of irony.

"I think it's just kind of Katie's revenge."

Jackson County Prosecutor Steve Pierson speculated that it had to be a guard who took and smuggled the picture out of the prison, since inmates are prohibited from having cameras.